Just as a triangular number is a number that can appear as a triangle, so a square number can take the form of a square. 25 is a square number. If we call 1 the first square number, then by adding what gnomons was 25 produced?

When the same number is repeated as a factor three times -- as 2 × 2 × 2 -- we call the product the 3rd power of that base; that product is commonly called a cube. (This is analogous to the volume of the solid figure called a cube.)